Fetches the latest version of a package from its official registry. Supports npm, PyPI, crates.io, Maven, Go, RubyGems, NuGet, Packagist, Hex, pub.dev, Homebrew, and Conda. Use prefix like
AI agents call e_check_package_version to retrieve information from Heuristic without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Even though e_check_package_version only reads data, uncontrolled read access leaks sensitive information and racks up API costs — an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
Fetches the latest version of a package from its official registry. Supports npm, PyPI, crates.io, Maven, Go, RubyGems, NuGet, Packagist, Hex, pub.dev, Homebrew, and Conda. Use prefix like. It is categorised as a Read tool in the Heuristic MCP Server, which means it retrieves data without modifying state.
Register the Heuristic MCP server in PolicyLayer and add a rule for e_check_package_version: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Heuristic. Nothing to install.
e_check_package_version is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the e_check_package_version rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for e_check_package_version. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
e_check_package_version is provided by the Heuristic MCP server (softerist/heuristic-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.